FIG. 5 is a perspective view of conventional angular velocity sensor 500 disclosed in PTL 1. Angular velocity sensor 500 includes fixing section 1 having a rectangular parallelepiped shape, sensing-electrode vibrating segment 2 having one end connected to fixing section 1, and sensing-electrode vibrating segment 3 having one end connected to fixing section 1 and extending opposite to sensing-electrode vibrating segment 2. Sensing-electrode vibrating segments 2 and 3 are made of piezoelectric single crystal. A sensing electrode is provided on an upper surface of sensing-electrode vibrating segment 2. A sensing electrode is provided on an upper surface of sensing-electrode vibrating segment 3. Bent section 4 extends from another end of sensing-electrode vibrating segment 2 perpendicularly in a left direction. One end of connection beam 5 is connected to bent section 4 and is bent perpendicularly in an X-axis direction. Driving-electrode vibrating segment 6 made of piezoelectric single crystal has one end connected to connection beam 5. A driving electrode is provided on an upper surface of driving-electrode vibrating segment 6. Bent section 7 extends from another end of sensing-electrode vibrating segment 2 perpendicularly in a right direction. Connection beam 8 has one end connected to bent section 7, and is bent perpendicularly in the X-axis direction. Driving-electrode vibrating segment 9 made of piezoelectric single crystal has one end connected to connection beam 8. A driving electrode is provided on an upper surface of driving-electrode vibrating segment 9. Bent section 10 extends from another end of sensing-electrode vibrating segment 3 perpendicularly in the left direction. Connection beam 11 has one end connected to bent section 10 and is bent perpendicularly in the X-axis direction. Connection beam 11 is connected to another end of driving-electrode vibrating segment 6. Bent section 14 extends from another end of sensing-electrode vibrating segment 3 perpendicularly in the right direction. Connection beam 15 has one end connected to bent section 14. Sensing-electrode vibrating segment 3 is bent perpendicularly in the X-axis direction. Another end of connection beam 15 is connected to another end of driving-electrode vibrating segment 9.
An operation of conventional angular velocity sensor 500 will be described below.
Upon having an alternating voltage applied to the driving electrodes provided on driving-electrode vibrating segments 6 and 9, driving-electrode vibrating segments 6 and 9 are driven to vibrate in a driving direction at velocity V. While driving-electrode vibrating segments 6 and 9 vibrate, angular velocity sensor 500 rotates at an angular velocity ω about a Z-axis perpendicular to a plane including angular velocity sensor 500, thus causing driving-electrode vibrating segment 6 to generate Coriolis force F(=2 mV×ω). Coriolis force F is transmitted to sensing-electrode vibrating segment 2 via connection beams 5 and 8 and bent sections 4 and 7, and is transmitted to sensing-electrode vibrating segment 3 via connection beam 11, connection beam 15, and bent sections 10 and 14. As a result, angular velocity sensor 500 outputs an output signal according to the angular velocity from the sensing electrodes provided on the upper surfaces of sensing-electrode vibrating segments 2 and 3. However, angular velocity sensor 500 may provide a small output signal generated due to Coriolis force F.